Monday, October 4, 2021

October 2, 2021 - Fall Diversity - Kate Sutherland

Hurricane Sam was passing to the east of Bermuda over the weekend giving us just a bit of uncertainty about how much swell would reach us here in Hatteras and if it would cause any trouble for us getting across the bar and to the sea via Hatteras Inlet.  We were very happy to find things were quite nice for us to get out on Saturday with a long period easterly swell and north easterly winds setting us up for some good  conditions for seabirding!  Reports of shearwaters on the shelf had us searching the horizon as we headed offshore.  Around 0830 we found a nice flock of over a hundred shearwaters giving us the opportunity to show everyone Cory's, Scopoli's, Great,
and Audubon's Shearwaters sitting on the water and in flight!  The shelf came and went around 0930 and we started dripping some oil, but it took a little while for us to find our first Black-capped Petrels in the deeper water.  They seemed to be mostly sitting around early and we kept seeing small groups suddenly appear in the air around us.  Once we slowed and put more chum out, Wilson's Storm-Petrels found the slick and Black-capped Petrels started checking it out as well.  The Gulf Stream current was moving about 2-3 knots and with the wind against it, seas were a bit choppy in addition to the longer period swell from Hurricane Sam.  Sargassum, the brown algae with air bladders that is a typical feature of the Gulf Stream, was scattered around which meant Audubon's Shearwaters were out there and we had some nice views of these small black and whites offshore.  Just a handful of larger shearwaters were in the deep in contrast to the shelf waters, but that's okay because we had Black-capped Petrels out there! 
They were really showing off on Saturday and we had a number flying incredibly high before swooping down toward the sea.  Many times there would be two or three in a group arcing up into the sky before flying down one after another.  Our following group grew over the course of the morning and we had eight or nine back in the slick when I saw them chasing what looked to be a larger, pale bird way back behind us.  We circled back to get a better look and a pale Northern Fulmar came flying toward the boat!!  With a few Black-capped Petrels in tow.  
It was interesting to see the Black-cappeds exhibiting this behavior for a fulmar, because we typically see them harassing dark jaegers and skuas in this fashion.  A few petrels flying up behind the target bird and coming close, but not making contact, before veering away.  As many as six or seven Black-cappeds would work together to chase the fulmar, seeming to harass it and encourage it to leave the area. 
But, in true scrappy fulmar style, this bird was not deterred, and stayed with us feeding in the slick for almost an hour and a half!  Since we have seen larger birds like skuas feeding on dead Black-capped Petrels at sea in the past, we thought this behavior was akin to mobbing, a way to ward off a bird that is a threat to them.  But is it possible this behavior could be related to food?  A Black-capped Petrel exhibiting kleptoparasitism on Red-billed Tropicbirds was observed in the Cape Verde Islands recently (Peter Stronach personal comm).  It was pursuing these tropicbirds like a jaeger would until they dropped some food which the petrel would take.  The fulmar was larger than the Black-cappeds, so perhaps size could be a trigger for this behavior as opposed to coloration?  But we see them charge young Sooty Terns and Long-tailed Jaegers as well and Peter Flood photographed one pursuing an Audubon's Shearwater, all of which are slighter or smaller than a Black-cap.  We also regularly see them chasing one another around and Saturday we heard them calling as they fed on some chum together in a small group.  I imagine this behavior is more complicated than we know and we hope to compile all of our interactions into a note soon.
Once we got back to the shelf in the afternoon activity died down a bit so we picked up some speed to head back to the inlet.  As we were running along some of our participants saw what looked like a jaeger back at 0500, some distance from the boat.  Brian turned around to check it out and we found quite a nice little condition with some Sargassum and a number of birds!!  A young Long-tailed Jaeger was the bird that got our attention first and as we watched it it flew up into the sky in pursuit of something...
that was a young Sabine's Gull!!!  WOW!  The gull was obviously in distress as it tried to avoid the slightly larger jaeger on its tail, and it quickly disappeared into the sky presumably after giving up its last meal for the jaeger.  There were some cooperative Red-necked Phalaropes on this change and a number of Cory's type, Great, and Audubon's Shearwaters as well!  What a treat for the end of the day!  We have two more trips this fall, so hopefully this diversity will continue.
Thank you to everyone who joined us this weekend and thanks to Ed Corey for helping us to lead the trip!  Always a joy!  Photos in the post today are all mine - we might add some from Ed next week.

Species List for October 2, 2021
Northern Fulmar - 1
Black-capped Petrel - 58 to 71
Cory's Shearwater - 11
Scopoli's Shearwater - 11
Cory's / Scopoli's Shearwater - 216
Great Shearwater - 24
Audubon's Shearwater - 34
Wilson's Storm-Petrel - 60
Red-necked Phalarope - 7
Sabine's Gull - 1 immature
Long-tailed Jaeger - 1 immature
jaeger species - 1
Herring Gull - 3
Bottlenose Dolphin (Offshore population) - 11 to 12

Also seen on the shelf:
Lesser Black-backed Gull - 1
Laughing Gull - 24 to 26
Common Tern - 103
Atlantic Spotted Dolphin - 7

First, a few more images of the Black-capped Petrels and Northern Fulmar...
Black-capped Petrels were looking pretty sharp out there!
This one feeding on some chum looks to have a hole in the webbing of its foot!
We had a number of Cory's Shearwaters out there but most of my photos were distant.  Here is a nice view of what looks like perhaps a male Scopoli's.
There were a number of Cory's types that were not obliging in showing their underwings!  But we had a great time watching them feed in the Sargassum.  This one has an Audubon's Shearwater that just dove next to it!
Great Shearwater showing off the inside of its mouth and how they are able to keep ahold of those fishes and squid they like to eat!
An Audubon's flying near some Sargassum on the shelf in the afternoon.  Tough light, but you can see the long tail with dark under tail coverts.
Wilson's Storm-Petrels were super obliging during the offshore portion of the day showing off their long legs and even the yellow webbing on their feet!
One of the flyingfish that we encountered!  This individual doesn't seem to show dark pectoral fins like a blackwing flyer (Hirundichthys rondeletii), but otherwise looks quite similar to one.  Always interesting to see, photograph, and attempt to identify these awesome fishes!

Monday, September 27, 2021

Saturday September 25, 2021 - Kate Sutherland

Friday was a blustery day and we hoped the winds would calm enough to get offshore on Saturday...well luck was with us and Saturday morning winds were blowing about 12-17 mph from the north.  Skies were partly cloudy as we headed offshore into a sea that was calmer than expected, but still a bit choppy once we made it out of the lee of Cape Hatteras.  As we approached the shelf break, there was a temperature break with a bit warmer water on the offshore side, a Long-tailed Jaeger came zipping by on this feature and we started seeing some Cory's type shearwaters popping up around us on the horizon.  We saw our first Black-capped Petrel of the day on the shelf!  Certainly not a bad start! (Kate Sutherland)
Gulf Stream current was running a bit as we moved offshore into deeper water and the wind against the current made the seas a little larger than they had been, but this also had the birds moving, and we found our first feeding flock of shearwaters in the 0900 period.  This flock was composed of mostly Cory's type shearwaters, but we also had views of our first Great and Audubon's Shearwaters of the trip here as well.  Both were cooperative, and a few Black-capped Petrels were in the area too.  It was nice to see some Wilson's Storm-Petrels in with the feeding flocks and we were able to entice a few to follow us with our fish oil slick, allowing participants to study them for most of the day as they showed off their long legs and short, paddle-shaped wings. (Kate Sutherland)
As we continued offshore, we kept seeing feeding flocks arc up on the horizon, a couple of these were easy to keep an eye on since they had their attendant Sooty Terns flying up high over the action.  One of these groups with terns we finally caught up to and we could hear them calling as they flew overhead, quickly moving off with the shearwaters.  These feeding flocks are moving with the fish below the surface and also with the wind, so a few flocks we were unable to catch, and others we were able to just stay with for a short time before they moved along.  It was nice to see so much activity in late September, but this is a time of year when we just run a few trips, so we still have a lot to learn about what to expect!  We do tend to see more land birds and coastal species in the fall, and we had at least three young Herring Gulls and a young Lesser Black-backed Gull following us for most of the day!  A Tree Swallow and a few Barn Swallows also checked out the boat many miles from shore!  Once we put out the chum and birds started following the boat, we had really good views of Black-capped Petrels and Wilson's Storm-Petrels right behind us.  Jaegers were also around in the deep and we had a young Parasitic Jaeger fly by offshore, then a couple more cooperative Pomarine Jaegers, one of which stayed with us for over an hour! (Kate Sutherland)
The show wasn't over once we left the blue water of the Gulf Stream...we found two Red-necked Phalaropes and had a fly-by Sooty Shearwater in the cooler, greener shelf waters.  Overall an excellent day offshore!  Thanks so much to everyone who joined us making this trip possible, and a big thank you as well to Jason Denesevich for helping us lead the trips!  We're excited to make it out there three more times this fall, and we still have space on the last two trips - Oct 9(10) and 23(24) - come see what we can find!

Species List for September 25, 2021
Black-capped Petrel - 37 to 38
Cory's Shearwater - 3
Scopoli's Shearwater - 16
Cory's / Scopoli's Shearwater - 550 to 555
Great Shearwater - 78 to 79
Sooty Shearwater - 1
Audubon's Shearwater - 55
Wilson's Storm-Petrel - 43 to 44
Red-necked Phalarope - 2
Phalarope sp. - 11
Sooty Tern - 6
Sooty / Bridled Tern - 4
Pomarine Jaeger - 2
Parasitic Jaeger - 1
Long-tailed Jaeger - 1
Jaeger sp. - 2
Herring Gull - 3 to 4
Lesser Black-backed Gull - 1
Barn Swallow - 3
Tree Swallow - 1
Offshore Bottlenose Dolphin - 8 to 10
Loggerhead Turtle - 1
Cloudless Sulphur - 1

Black-capped Petrel dorsal and ventral views (Kate Sutherland).  All of the individuals we saw were sharp looking like these!  We saw both types of Black-cappeds (dark and light forms) plus a number of intermediate looking birds.
It is a lot harder to get on Scopoli's Shearwaters when they're not following us in the slick!  But we did have some nice views of them in the feeding flocks we found.  (Kate Sutherland)
And a couple of the Cory's Shearwaters we saw - I only photographed three of these out of 25 I had images of.  Pretty interesting to know that we still have a number of Scopoli's here offshore from Hatteras in late September!  (Kate Sutherland)
A dorsal view of one of the Cory's types we saw (Kate Sutherland)
And one of our young Herring Gulls!  (Kate Sutherland)

Thursday, September 9, 2021

September 4 & 5, 2021 - Shearwaters and Sooty Terns - Kate Sutherland

 Labor Day Weekend looked interesting with northeasterly winds on Saturday and light and variable winds on Sunday coupled with some easterly swell, so our hopes were high as we headed out into choppy seas on Saturday!  The features for both days were shearwater flocks, these flocks were pretty easy to spot thanks to the Sooty Terns flying above most of them.  We love beehives, the term we use for feeding flocks of seabirds, because you just never know what you might find in them.  Luck was on our side and we had excellent views of a number of species in these flocks over the course of the weekend.  In today's post I think we'll walk through each day, for while they had similarities in the form of these multi-species feeding flocks, each was also unique.
Saturday we had some wind so it was choppy and we headed in our usual direction to the south southeast in the morning.  We started to see shearwaters and had a couple of Bridled Terns before we even reached the shelf break!  Then we had what looked like a young Black-capped Petrel join us to check out the fish oil slick soon after we crossed into the slope waters.  Interestingly enough, we had a couple of Black-cappeds with us at the end of the day as we approached the shelf!  Usually these sharp looking gadfly petrels are in deeper water (Kate Sutherland).
Our first feeding flock had almost 30 Sooty Terns associated with it and it was incredible to hear the young birds as they swooped over the boat with their parents nearby (youngster by Ed Corey).
We had Scopoli's, Cory's type, and Audubon's Shearwaters in this group along with some Black-capped Petrels and Wilson's Storm-Petrels.  A Band-rumped Storm-Petrel briefly visited the group but did not show very well, and an immature Pomarine Jaeger was chasing Audubon's around also!  The next flock had fewer Sooty Terns but held a couple of Great Shearwaters and a young Long-tailed Jaeger!  There were also some Red-necked Phalaropes in the area (Ed Corey).
Just before noontime we finally had a more cooperative Band-rumped Storm-Petrel and a good number of Wilson's Storm-Petrels stayed with us throughout the day!  
By Sunday the wind had fallen out and we had calm seas.  The Gulf Stream Current, which had been slack on Saturday (we even had reports of some down current), was again not running hard close to Hatteras (less than a knot), so we headed to the east!  This put us a bit north of the ground we would usually cover and we were hoping to see what type of life was up there without running the risk of being swept too far to the north by the Gulf Stream.  Again we had Cory's, Scopoli's, Cory's type (Kate Sutherland), and Audubon's Shearwaters on our way offshore.
There were also a number of Common and Black Terns around.  Just over the shelf break we began to see flocks of shearwaters on the water and feeding, mostly Cory's types, and we began to travel from flock to flock to see what we could turn up!  Again we had the Sooty Terns attending the flocks with the calling juveniles and adults, one of these flocks also had a couple of Bridled Terns and we were able to see the differences between the larger, darker Sooty Terns and the smaller Bridleds with their grayer backs, pale napes, and whiter under primaries!  We were moving from flock to flock for most of the day and had over 400 Cory's types tallied by the time we reached the shelf break again in the afternoon.  Black-capped Petrels and Wilson's Storm-Petrels were cooperative in the slick, but we didn't turn up a Band rumped on Sunday.  We did, however, find a perched adult Bridled Tern that allowed us to approach for incredible views and we saw its youngster a few minutes later checking out some schools of small flyingfishes and Balao, a cousin to the Ballyhoo!  There was a lot of life out there so of course I wanted to dip some Sargassum and see what we could find...and while a few of us were sorting through that two young Long-tailed Jaegers flew in to check us out (Ed Corey)!
It has been a really good summer for seeing them!  Two participants found a Sargassumfish in one of the dips and everyone who was interested had a chance to see it plus our other finds (more information about them in the photo section) before we put them back with their floating habitat!  We had a glimpse of a Cuvier's Beaked Whale before it sounded, a nice pod of bow riding Atlantic Spotted Dolphins, and even a Loggerhead Turtle to round out the list! 
Overall a great set of trips, and our last weekend of the year to run a couple back to back.  The rest of our fall trips are Saturdays with an obligatory weather date on Sunday and we have space on our next departure on September 18 (19)!  Thank you to everyone who joined us out there and a big thank you to our leaders, Ed Corey and Paul Laurent, for helping us out!  Ed also contributed photos for this post, thanks, Ed!! 

Species List for September 4 / 5
Black-capped Petrel - 37 to 40 / 26 to 27
Cory's Shearwater - 4 / 13
Scopoli's Shearwater - 29 / 14
Cory's / Scopoli's Shearwater - 118 / 415
Great Shearwater - 5 / 52 to 53
Audubon's Shearwater - 21 / 49
Wilson's Storm-Petrel - 86 / 93
Band-rumped Storm-Petrel - 2 to 3 / 0
Red-necked Phalarope - 11 to 12 / 2
Phalarope sp. - 0 / 1
Sooty Tern - 41 / 42 to 43
Bridled Tern - 2 / 4
Sooty / Bridled Tern - 0 / 3
Black Tern - 6 / 11
Pomarine Jaeger - 1 / 0
Long-tailed Jaeger - 1 / 2
American Redstart - 0 / 1 came aboard
Cuvier's Beaked Whale - 0 / 1
Atlantic Spotted Dolphin - 0 / 12 to 15
Silver-haired Bat - 0 / 1
Bat sp. - 0 / 1
Loggerhead Turtle - 0 / 1
Monarch - 0 / 2
Cloudless Sulphur - 3 / 7
Common Green Darner - 0 / 1

This Black-capped Petrel had very dark underwings!  (Kate Sutherland)
We saw a handful of Cory's Shearwaters over the weekend (Ed Corey)
And more Scopoli's Shearwaters, here you can see one in the center of this feeding group that is composed of Cory's types, Scopoli's, and Great Shearwaters (Kate Sutherland)
A Cory's type shearwater (Kate Sutherland)
Great Shearwaters were very cooperative near the boat! (Kate Sutherland)
As were Audubon's Shearwaters!  This was a treat because sometimes these small black and white shearwaters can be a bit boat shy.  (Ed Corey)
Audubon's are usually found around Sargassum since they feed on the creatures associated with this floating brown algae.  This one dove next to us and surfaced with some on its back! (Kate Sutherland)
A couple more views of some Sooty Terns!  Here is an adult and the underside of a juvenile (the upperparts are visible in Ed's photo in the blog text!) (Kate Sutherland)
And for comparison, here is the perched Bridled Tern from Sunday.  You can see the back is much grayer than the adult Sooty Tern pictured above.  (Kate Sutherland)
Here are a few pictures of the cooperative Atlantic Spotted Dolphins!  A typical spotted individual (top - Kate Sutherland) and a couple of typical younger individuals without spots below (Ed Corey).


It was really cool to see these schools of fish leaping from the water near the boat, but very easy to get a good photos of them!  These look like Balao (Hemiramphus balao). (Kate Sutherland)
And some young flyingfish!  (Kate Sutherland)
We found some really cool creatures in the Sargassum that we dip netted!  Here are participants Heather Levy and Peter Kleinhenz checking them out in some of our trays.  The weather has to cooperate for us to be able to do this! (Kate Sutherland)
Here is a closeup of the Sargassumfish (Histrio histrio) in some Sargassum natans, one of the species of Sargassum we commonly find offshore from Hatteras. (Kate Sutherland)
This photo has four different species, three fishes and one crab, in addition to the Sargassum natans you can see hydroids (the feathery looking creatures) and bryozoans (the crusty looking covering on the algae are their homes!) attached to the algae!  There are about 50 obligate species that are associated with Sargassum!  (Kate Sutherland)
Here is a closer look at the Sargassum Pipefish (Sygnathus pelagicus) and the Sargassum Swimming Crab (Portunus sayi) - the other creatures in the photo above are Planehead Filefish (Stephanolepis hispidus), and the Sargassumfish! (Kate Sutherland)